Oil pump for transmissions



March 3, 1942. w, os1- 2,274,836

OIL PUMP FOR TRANSMISSIONS 7 Filed Dec. 22, 1938 W BY WWM exp mb dies-exle evere str ner eet that I; zamaxiahmextendineidis fitesatiheslubrifiantrtbethetd fianism .Of; ithisztypewheiieim nece sary.fi eating inneller; vaneawhichofunctidnsa short and compa tdesigmyrequirin'giziviery; little-r.

space in the tr nionand1,.:being ofysuch; Character hat it is readilymanufacture-(land assembled and is efiectiveinoperation. 1

An object of the invention,accordinglypisto provide an improved pumpstructure adapted. particularly for use in connection withftrans-zmission mechanisms wherein the operating Parts are of such character asto pump the oil efliciently while subjecting it to no unnecessarypressures, thus avoiding unnecessary heating oi the oil. m

A further object of the invention is to provide a pump of the abovecharacter wherein the parts are simple in construction and assembly andfunction eil'ectively during operation.

' Further objects will be apparent from a more detailed description ofthe invention in connection with the accompanying drawing, wherein:

Figure 1 is a view in broken section, taken on the broken line l| ofFigure 2 and'looking in the direction of the arrows;

present iinvtentioncprovidesv e. oil iSEGiitlIfily elimmatedci isLkeye d;to thesh rtete{atria and? thus is 'drivenz IJ V. .e and. v .tgainer-Aimee.

ran m ssicn chamber 118 teicover or ousmma-p o communication betweenthegductzi and thespumpe chamber Ruby means of:;-arconununicatingw-slo 1by the shaft. Th'ezshaft;I8 and-the sleev z3lzare disposed eccentricallywith respect to the axisof the pump chamber 23 to provide: a crescentshaped space for: cooperation with :a; unitary impeller member 33 towithdraw. liquid through the inlet 30. The sleeve is formed with radialbores 33 which communicate-withthe-xduct 23 and are adapted to receiveimpeller vanes carried by the unitary impeller member 3% The unitaryimpellermember 34 is formed with an intermediate reduced portionasindicated at 35. the extremities of the impeller member being formed asvane, members 33 which are slidably received in thebores 33. The lengthof the impeller memher is such that the ends of the vane members slideover the peripheral wall of the pump cham- Flgure 2 is a view intransverse section, taken 5 bet 33,'as will'be clearly seen in Figure 2.

As viewed in Figure 2, the direction of rotation, when the device is inoperation, is counterclockwise and, in order that the oil from the pumpchamber 29 may b supplied undersufllcient pressure to the duct 23,discharge ducts 31 are provided in the sleeve 3| and communicatingbetween the pump chamber 29 and the extremities of the bores 33 adjacentthe bore 23, It will be observed that the vane members 36 are formedwith inner edges 38 which function as valves to cut oficommunicationbetween the discharge ducts 31 and the bores 33 at the moment that therespective vane members cease to function to pump .oil into the bore 23.In this fashion, all of the oil trapped and pumped by the vane memberswill be driven through the discharge ducts 31 and supplied to thelubricating system. At no time oil be trapped in the pump chamber and beunable to escape therefrom through the dis- 1 {charge ducts. Thisprovides an efiective mechanism not only for actually pumping the oil,but for valving it through the discharge ducts and tothe distributingsystem.

In order that pressure within the pump chamber may be maintained, spiraloil grooves 39 and 40 are formed in the sleeve. 11 oil should leak bythe spiral groove 39, it will drain back into 4 i the transmissioncasing through a duct 4| formed in the bearing cover 28 andcommunicating with ducts 42 and 43, in the retainer and transmis- 'sionwall respectively.

An additional spiral oil groove 44 is formed intheshait II to preventleakage along the shaft, thusmaintalning an effective and oil-tight pumpmechanism. It will be observed that the sleeve 3| 1 is retained inposition by a nut 45 which is threaded onto a portion of the drive shaftll. innerrace II in the position shown. The timing of the valve actionof the lower edge 38 or the vanes 361s governed by the position of theimpeller member in the eccentric pump chambe'r ZS'. The foregoingconstruction provides discha ge ducts which permit all of the pumped oilto pass through the pump and into the lubricatins system. The oil flowis not shut oil. until and the outletports formed by the discharge iducts are quite large in area and stay open until alliof the pumping hasbeen accomplished. By

providing an adequate area of outlet port, foaming or the oil is avoidedand the operation of the 1 mechanism is highly emcient.

It will be observed that the simplicity of the structure makes ,tor easyassemblyand fficient ,Operation. .The impeller member is symmetrical anddoes not depend for efflcient operation upon any particular positionwithin the bore. The mechanism is compact and requires very littlespacein the transmission, being easily assembled in the bearing cover28.

While the invention has been described with specific reference to thestructure shown in the accompanying drawing, it is not to be limitedsave as defined in the appended claims.

I claim: l. A rotary pump comprising a circular housing, a rotarycylindrical body disposed eccentrically with respect to the axis of saidhousing to provide a substantially crescent-shaped chami ber therewith,said housing having an inlet for said chamber, said cylindrical bodyhaving a transverse bore therethrough, a cylindrical vane memberextending through said bore and adapted to reciprocate therein when saidbody is ro- This nut also serves to retain the' the v'ane head is at thelowest end or its stroke tated. said vane member having a lengthsumcient to provide a close running fit in said housing and the innerportions of said vane member having a reduced diameter to provide anannular passage in said bore, said cylindrical body having an axial.outlet passage communicatingwith said annular passage and passages adjacent the leading sides or the end portions of the vane member andextending from the periphery of said body into said annular passage, theinner ends of the last named passages being located where the largediameter end portions of the vane member will block said passages whenthe ends of said vane member are in their inner poportions of said vanemember being cylindrical.

and interconnected by a reduced portion to provide a passage insaidbore, said cylindrical body having an outlet passage communicatingwith the passage portion or the bore and inlet passages adjacent theleading sides of the end portions or the vane member and extending fromthe'periphery of said body into said bore, the

inner ends of the last named passages being 10- cated'where the endportions of the vane member will block said inlet passages when the endsof said vane member are in their inner positions.

3. 1A rotary pump comprising a circular housing, a rotary cylindricalbody disposed eccentrically with respect to the axis of said housing toprovide a substantially crescent-shaped cham- I ber therewith, saidhousing having an inlet for said chamber, said cylindrical body having atransverse bore therethrough, a vane member extending through said boreand adapted to reciprocate therein when said body is rotated, said vanemember having a length suflicien-t to pro-" vide a close running fit insaid housing, the end portions of said vane member being cylindrical andinterconnected by a reduced portion to provide a passage in said bore,said cylindrical body having .an outlet passage communicating with thepassage portion of the bore and inlet pas sages at'the leading sides ofthe end portions of the vane member and so disposed as to havecommunication with the passage portion of the bore when the end portionsof the vanes are in fluid irnpelling positions and to be blocked by saidend portions when they are in their inner positions.

shaft having openings coaxial with said bore, a

housing having a circular wall portion disposed eccentrically withrespect to the sleeve to provide a substantially crescent-shaped chambertherewith, said housing having an inlet for said chamber, a vane memberdisposed in said bore and extending through the openings in said sleevefor reciprocation therein when said shaft is rotated, said vane memberhaving a length suflicient to provide a close running fit in saidhousing, the end portions of said vane member being cylindrical andinterconnected with a rethe end portions of the vane member will blockthe passages when the end portions 01' said vane member are in theirinner positions and will permit communication between said passages andthe passage portion or the bore when said end portions are in fluidimpellingpositions.

WmLIAM- A. KOSTER.

